Effects of irrigation amount regulation of corn straw anaerobic return-ing on spinach production

CAI Xingdong; WANG Li; XU Faming; DONG Haobing; ZHANG Qin; WEN Xiaobing; WANG Yu; CHEN Sijin; SUN Xiaomei

doi:10.16861/j.cnki.zggc.2025.0133

Abstract：In order to explore the effects of corn straw returning on soil characteristics,as well as the growth and yield of spinach under different anaerobic durations,four treatment groups were set up:Corn straw not returning to the field(CK),corn straw returning to the field(T1),corn straw returning to the field+watering once to make the soil water holding capacity saturated(T2),corn straw returning to the field+watering twice to make the soil water holding capacity saturated(T3).The results showed that compared with the control,the in-situ anaerobic return of corn straw significantly decreased the soil pH.The soil moisture content and organic matter content under T3 treatment were significantly higher than those under other treatments,with the organic matter content in T3 being 31.5％,19.9％and 15.4％higher than that in CK,T1 and T2,respectively.With the increase of irrigation times,the soil conductivity showed a downward trend.Compared with the control,corn straw returning in-situ significantly increased the content of ammonium nitrogen by 11.1％,16.0％and 15.1％in T1,T2 and T3,respectively.However,the content of nitrate nitrogen decreased by 8.3％,11.3％and 23.9％under T1,T2 and T3 treatments,respectively.The content of soil available phosphorus and potassium significantly increased in T1,T2 and T3 treatments by 51.7％,25.7％,24.0％and 10.3％,9.8％,19.0％,respectively.The weed biomass under T3 treatment was significantly lower than that under CK,T1 and T2 treatments by 92.4％,91.5％and 53.3％.The plant height of spinach in T2 and T3 treatments was significantly higher than that in CK and T1 treatments.The leaf area of T1,T2 and T3 treatments was significantly higher than that of CK by 10.5％,20.2％and 20.0％,respec-tively.The yield of spinach in T2 and T3 treatments was 27.9％and 39.5％higher than that in the control,respectively.Random forest analysis showed that soil electrical conductivity,water content,nitrate nitrogen content,available phosphorus content,pH and total chlorophyll content,net photosynthetic rate,leaf area could explain more than 7％of the variation of spinach yield.In conclusion,with the increase of irrigation times,the in-situ anaerobic returning of corn straw can signifi-cantly reduce soil pH and nitrate content,increase soil organic matter,ammonium nitrogen,available phosphorus and available potassium content,and promote the growth and yield of spinach.